LICHTMAN: Yeah, a bat cave, a few actually. And our tour guide is Nick Hristov, who is affiliated with UNC and Winston-Salem State University. And the thing to know about him is that he is, like, a naturalist 2.0. This is like Charles Darwin updated for the 21st century. And that is good news for us, because it means - and what I mean by that is that he takes really cool videos using very high-tech gadgets.

So in his tool kit are laser scanners and IR cameras that he takes into caves. And some of the most beautiful footage is just color, high-speed video that's 1,000 frames per second of these caves - of these bats pouring out of caves, thousands of bats per minute. And when you slow it down, it goes from this sort of stream of black - that's what it looks like in real time - to individual bats flying over your head. I really like it.

FLATOW: Wow, that's great.

LICHTMAN: I really like the video footage.

FLATOW: This is SCIENCE FRIDAY, from NPR. I'm Ira Flatow, talking with Flora Lichtman. Our Video Pick of the Week is up there on our website. And, you know, how do you describe this? You know the slow motion you see the geese flying sometimes? Imagine hundreds of thousands of bats...

LICHTMAN: Yes.

FLATOW: ...in that kind of - ever slower motion.

LICHTMAN: Yeah, and in beautiful color. I mean, this is - he's really an artist and biologist at the same time. And he also takes us into the cave, and we have a little audio clip of Nick describing what that experience is like.

(SOUNDBITE OF ARCHIVED INTERVIEW)

NICKOLAY HRISTOV: Going into the cave is yet another experience, one that I often refer to as one of the most disgusting and at the same time fascinating experiences in my life.

LICHTMAN: Disgusting because?

HRISTOV: You're walking on a 10-meter carpet of bat poop.

LICHTMAN: Fascinating because?

HRISTOV: It is like a cathedral of nature.

LICHTMAN: So, a 10-meter carpet of bat poop. And it's also really hot, he also told me.

FLATOW: That's what - yeah.

LICHTMAN: But, fortunately, that doesn't translate in IR video, at least the bat poop. So you get to go in without the disgusting stuff and see just kind of like lava flows of bats inside the cavern and see what they do during the day.

FLATOW: Right. And he's in this dark cave. It's black, but since he's using infrared cameras...

LICHTMAN: Right.

FLATOW: ...it looks like that - like you say, red, like lava all over the walls.

It's really crazy. I don't know about you, but I always thought bats slept during the day.

Yeah.

Right?

Yeah, sure.

LICHTMAN: I feel like that's a sort of common - the common thought. But if you go in with these cameras, you see there's a lot of action. He said territorial disputes. They're flying around. So - that was sort of a little myth buster for me, anyway.

LICHTMAN: And, you know, he's got - I mean, in terms of the bat caves, he also looks at the morphology of the caves. So that's what he does with this laser scanner. Basically, you take a laser scanner, and it beams laser beams at the sides of the caves. Those take distance measurements, compile them into a point cloud, and then your computer puts them together into a 3D...

FLATOW: That's right. That's right.

LICHTMAN: ...reconstruction of the inside of the cave. So you can fly through it like you're a bat.

FLATOW: And just like - and almost like the movie. I mean, you can - this is a great video tour, a reconstructed 3D image flying through the cave in the video there.

LICHTMAN: Yeah. Yeah. This video is, you know, it's Nick Hristov's footage, and it just gives you a different sense of the life of bats. I think I - I certainly didn't have any sense of before this.

FLATOW: Yeah. And so he set up. Well, you went out there, set up his cameras, and there's a great opening shot of - how many bats where in this cave?

LICHTMAN: Thousands per minute, and there's like 200 to 500,000 bats living there in this colony. And this is in South Central Texas, and these are free-tailed bats, for people who are interested. He also has some really beautiful footage, of course, of a bat in the flight lab. Again...

FLATOW: Right.

LICHTMAN: ...the detail is really...

FLATOW: Right. It's all up there on our website at sciencefriday.com. And, you know, it has that iconic view of the bats leaving the cave. What, is it sunset when they're going out?

LICHTMAN: Well, they most...

FLATOW: It looks like during the day almost.

LICHTMAN: Yeah. They mostly leave at sunset. But he said that on occasion, there are exceptions, and that's when he took this footage. And, you know, the point that he makes about his work is that even though he's using all of these cool, high-tech gadgets, you know, he sees this as naturalism of today, that he's not so different from these guys who walked around with a notebook recording. He just is using a different medium to capture what he's seeing.

FLATOW: A chiropterologist is - I see that as a...

LICHTMAN: All right. I never heard that word.

(LAUGHTER)

FLATOW: Nothing to do with your back problem.

LICHTMAN: I can't spell it. That's for sure.

FLATOW: So that's a study of, you know, things come in on the Internet, or you get Twitter...

LICHTMAN: Great.

FLATOW: ...or whatever. People will come in. Well, thank you, Flora.

LICHTMAN: Thanks, Ira.

FLATOW: It's our Video Pick of the Week. If you want to see something - it's really a beautiful video, not just of the bats in flight in super slow motion and you're like in the middle of them, but it's also this great reconstruction of the bat cave, computer simulation when, you know, how you fly through these things in computer simulation through the bat cave. And also infrared shots of the cave at night, in the dark. And you can see - it looks like lava because it's in red. It looks like the cave is just coated with the red stuff. The red stuff turns out to be these thousands and thousand of bats. Great stuff. Thank you, Flora.

LICHTMAN: Thank you, Ira.

FLATOW: That's about all the time we have for this hour. Transcript provided by NPR, Copyright National Public Radio.